Field of the Invention
The invention relates to a bone anchor including an anchor member with an expandable tubular section and a core member insertable into the anchor member and connectable thereto. The core member is configured to cooperate with the anchor member, such that by actuating the core member with respect to the anchor member, the tubular section is expandable. The anchor member is made from a material that is more flexible than a material of the core member. In particular, the bone anchor can be used in a bone fixation or stabilization arrangement, and is especially suitable for anchoring fixation or stabilization devices in osteoporotic bones.
Description of Related Art
US 2009/0131992 A1 describes an attachment device with a radially expandable section. The attachment device can have helical threads to facilitate screwing the attachment device into a bone. The attachment device can be positioned to radially expand the expandable section in cancellous bone substantially surrounded by cortical bone. In particular, the expandable attachment device can have an expandable thread on the expandable section and an unexpandable thread on the unexpandable section. It can be radially expanded by applying a distally-directed force to the distal end.
US 2011/0319946 A1 describes a device for deploying a bone implantation and stabilization assembly into bone tissue, e.g. a spinal structure, vertebrae, cancellous bone, cortical bone etc., in order to stabilize bones and/or bone segments. The bone stabilization device includes an anchor region in the form of an expanding tube or the like including a plurality of anchoring elements or arms that are deployable in a direction away from the axis of the assembly. An actuator is provided for deployment of the anchoring elements.